Not Applicable
Not Applicable.
If pipes are used for carrying media such as a gas it is necessary again and again to close a pipe end. Such a pipe closure may be required, for example, by the fact that a pipe line is not intended to be continued for a period of time. It is particularly in pipe line systems which are to be completed in several stages that there is frequently a need to temporarily close pipe lines that are intended to be extended later for a completion of the pipe line system. However, it may also be expedient to temporarily close the system while under construction to avoid contamination, for example.
For a closure of pipe line systems, it is known to weld a cap onto the end of the pipe. The disadvantage of such a closure of the pipe is that metal chips and impurities will be formed while the cap is separated. Such impurities require great expenditure in preparation before the pipe line is used again, specifically in pipes used in semiconductor factories, pharmaceutical installations or other points of application where increased demands are made to cleanliness. Before a restart of the pipe line, it is often necessary to thoroughly rinse the pipe line, which is time-consuming and involves high cost.
Also, proposals were made already to provide a device for closing a pipe at its end side, which is easy to manufacture, will tightly close the pipe, and can be easily removed therefrom without leaving behind any residues. To this end, one end of a flanged-socket metallic member is welded onto the pipe to be closed while its other end is designed for being orbitally welded onto a pipe joining it. The outer surface of the flanged-socket member has a chamfered surface which can be located at least axially towards the other end. A closing member adapted to be placed onto the other end of the flanged-socket member has a sealing surface adapted to bear against the front-end face of the other pipe and a second, circumferential outer chamfered surface. Such a device is suited for use in closing a pipe end to make it highly gas-tight. The flanged-socket member is fixed to the pipe to be closed, e.g. by welding it thereto. The clip which grips around the flanged-socket member, when mounted, presses the closing member onto the flanged-socket member. The advantage of the invention is that more pipes may be connected to the flanged-socket member once the closing member has been removed. Here, the form of the flanged-socket member is such that a further pipe may be fixed by orbital welding to the flanged-socket member. The removal of the clip and the closing member is easy and implies no entry of dirt or impurities into the flanged-socket member or pipe.
It is the object of the invention to provide an end-sided closure for a pipe which can be simplified even more and is particularly easy to handle.
At its outer surface, the end-sided closure according to the invention has a flanged-socket member which is welded onto the pipe to be closed. Its end is designed for being orbitally welded and is provided with a highly gas-tight closure. To this end, an annular flange which has axially parallel threaded bores at circumferential spacings can be formed on the flanged-socket member. Further, a closing member is provided which is designed in a cap shape and has a ceiling portion and an annular wall portion and is adapted to be placed onto the free end of the flanged-socket member. Here, the inside diameter of the wall portion of the cap-shaped closing member approximately corresponds to the outer diameter of the flanged pipe socket. At this point, the free end of the flanged pipe socket comes to sealingly bear against the inner face of the ceiling portion so as to form a metallic sealing.
The wall portion of the cap-shaped closing member has a series of through bores which are disposed at a circumferential spacing, are lined up in an axially parallel relationship, and can be aligned with the threaded bores in the annular flange. Finally, screws are provided which can be introduced into the through bores from the ceiling portion of the closing member and can be turned into the threaded bores of the flange to firmly press the cap-shaped portion against the free end of the flanged pipe socket. In this way, a tight closure that is efficient even if pressures or pressure differentials are very high will be obtained at the free end of the flanged pipe socket. In any case, this ensures that the pipe is closed so as to make it highly gas-tight at an approximate tightness of about 10xe2x88x929 1 annually. The flanged-socket member and the closing member specifically employ alloys of V4A steel. Using silver is advantageous, too.
The annular flange of the flanged-socket member is preferably rectangular in cross-section. However, this is irrelevant for the efficiency of the inventive assembly.
According to another aspect of the invention, the through bores terminate in outer pockets of the ceiling portion which receive the heads of the screws. This ensures that the screws do not protrude beyond the outer contour of the closing member so as to possibly form a danger of lesion. The countersunk arrangement of the screw heads is also ensured when the annular edge is provided with a pronounced chamfer between the wall portion and the ceiling portion.
According to an aspect of the invention, a flat metallic sealing ring preferably made of nickel can be disposed between the other end of the flanged-socket member and the inner surface of the closing member in order to further improve the sealing. For this purpose, according to another aspect of the invention, the inner surface of the ceiling portion can be provided with a circumferential shoulder which is close to the wall portion and against which the sealing ring will bear.
To further improve their accessibility by a tool, the head of the screws preferably have a hexagon socket.